The liquid crystal panel mainly comprises a Color Filter (CF), a Thin Film Transistor Array Substrate (TFT Array Substrate) and a Liquid Crystal Layer positioned inbetween. The working principle is that the light of backlight module is reflected to generate images by applying driving voltages to the two glass substrate for controlling the rotations of the liquid crystal molecules. According to the orientation of the liquid crystal, the liquid crystal display panels in the mainstream market can be categorized into several types, which are Vertical Alignment (VA), Twisted Nematic (TN) or Super Twisted Nematic (STN), In-Plane Switching (IPS) and Fringe Field Switching (FFS).
In the IPS mode or the FFS mode, by applying the electric field having the component basically parallel with the substrate, the liquid crystal molecules correspond in the direction parallel with the surface of the substrate and are driven.
Both the IPS liquid crystal display panel and the FFS liquid crystal display panel possess advantage of wide view angle. However, the wavelength of the blue light is shorter. Compared with the red light and the green light, the required retardation for reaching the same transmittance is smaller, and the transmittance-voltage curves of the red light, the green light and the blue light are different; besides, the transmittances of the red light, the green light and the blue light at the film interfaces of the PI film, PFA layer, OC layer and etc. in the panel are different, which also can cause the color washout problem.
For improving the aforesaid color washout problem of the IPS liquid crystal display panel and the FFS liquid crystal display panel, a method of improving the color washout according to prior art is shown in FIG. 1. The thickness of the blue color light resist B in the blue sub pixel area is increased for increasing the thickness of the CF substrate corresponded with the blue sub pixel area. Thus, the cell gap of the blue sub pixel area becomes smaller for achieving the objective that the balance white point generates the color difference; another method of improving the color washout according to prior art is to utilize the post circuit design to respectively adjust the GAMMA curves of the red light, the green light and the blue light to make the white dot chromaticity satisfy the optical specification.